1. Field of the Invention
The invention relates to an optical switch, and in particular, to a 2xc3x972 optical switch using a movable reflecting device to switch the optical path.
2. Description of the Related Art
An optical switch is a device which switches a light ray from one input terminal to a target output terminal and possesses the function of switching a transmitting path of the light ray to switch signal sources, receive terminals and failure points, etc. The optical switch is applicable in optical communication network node systems such as the optical cross connect (OXC) or optical add and drop multiplexer (OADM), so as to accomplish the functions of error restoration and exchange.
As shown in FIGS. 1 and 2, the conventional 2xc3x972 optical switch 1 includes four collimators 11, 12, 13 and 14 and six reflectors 101, 102, 103, 104, 105 and 106, wherein the reflectors 101, 104, 105 and 106 are fixed, and the reflectors 102 and 103 are movable. Referring to FIG. 1, after the collimator 11 has received a first ray R1, the first ray R1 is reflected by the reflectors 101 and 102 and is received by the collimator 12 to be output therefrom. In addition, after the collimator 13 has received a second ray R2, the second ray R2 is reflected by the reflectors 103 and 104 and is received by the collimator 14 to be output therefrom. Referring to FIG. 2, after the reflectors 102 and 103 are removed, the collimator 11 receives the first ray R1, and the first ray R1 is reflected via the reflectors 101 and 104 and is received by the collimator 14 and not by the collimator 12. The collimator 13 receives the second ray R2 and the second ray R2 is reflected via the reflectors 105 and 106 and is received by the collimator 14 and not by the collimator 12. In other words, when the reflectors 102 and 103 are removed, the light transmission path can be switched.
Although the conventional 2xc3x972 optical switch 1 achieves the objective of optical path switching, six reflectors are needed in this case. As a result, the cost of the switch is high, and the requirements for a light, thin, short and small in size of an optic-electro product cannot be achieved.
In view of the above, it is an imperative issue that needs to be overcome in order to reduce the production cost and to reduce the volume, weight and size of a 2xc3x972 optical switch.
Accordingly, it is an objective of the invention to provide an optical switch, which is light, thin, short and small in size and the cost of production of the switch is low.
In order to achieve the above objective, the optical switch includes two optical input terminals, two optical output terminals, two reflecting devices and a movable device. The optical input terminals are used to receive light rays. The two reflecting devices are positioned at a fixed position and the movable device reflects light rays. When the position of the movable device moves, the light rays are reflected by one of the reflecting devices and are selectively output from the optical output terminals.
As a result of change in position of the reflecting devices and the movable device, the objective of switching the optical path of the light ray can be achieved by means of two reflecting devices and a movable device. Thus, the production cost of the 2xc3x972 optical switch is greatly reduced, and in turn, the volume of the optical switch is reduced and the weight is lightened.